Interlocking transfer switch



Aug. 5, 1952 f J. F. FRESE 2,506,260

INTERLOCKING TRANSFER SWITCH Filed Sept. 19, 1.945 6 Sheets-Sheet l Aug.5, 1952 J. F. PRESE INTERLOCKING TRANSFER SWITCH Filed Sept. 19, 1945 6Sheets-Shee(I 2 Aug. 5, 1952 J. F. FREsE INTERLOCKING TRANSFER SWITCHFiled sept. 19, 1945 6 ShOBtS-Sheet 3 Aug. 5, 1952 J. F. PRESEINTERLOCKING TRANSFER SWITCH 6 Sheets-Sheet 4 Filed Sept. 19, 1945 Aug.5, 1952 .1. F. FRESE 2,506,250

INTERLOCKING TRANSFER SWITCH Filed Sept. 19. 1945 6 Sheets-Sheet 5A50/M32@ i @moa/j TEL-7 I ug. 5, 1952 J. F. FRI-:SE

INTERLOCKING TRANSFER SWITCH 6 Sheetgheet 6 Filed Sept. 19, 1945Patented Aug. 5, 14952 UNIT ED* STATES PATENT OFFICE INTERLOCKING'.TRANSFER SWITCH.

J osephzF.l Frese, Baltimore, Md.. assigner-to The Monitor ControllerCompany, Baltrnore.Md.',.

a, corporation of Maryland; Application" September/19,19.45`,\7Sc171alfNo. 617,264

7 Claims.; (Cl. 20098 My invention relates-broadly to higlfiv frequencyelectrical switches, and more particularlyf toa high frequencyinterlocking-:transfer switch.

Oneof the objects` of my invention isto provide a construction of-highfrequency-interlocking transfer switch in' Whlchsets of electricalkcontactors may be controlled in position where one set ofcontactorsi--is locked in one positionrepresenting one circuit`condition; while the other set of contactors is-lockedlin an oppositeposition representing anopposite circuit condition.

Another object of'v myinvention-vi's` to provide a construction of`high: frequencyelectrical switch having a pair-of sections forseparatelycontrolling the position of separatesets,`v of electrical contactorswith interlocking` meansv for preventing accidental movement of one setof contactors where another set-offfcontactorsfhas been pre-conditioned.

Still another object of my invention is vto provide a construction ofAhigh1 frequencyzinterlocking rtransfer switch, including mechanicalinter.- locking means associated with a pair of electromagneticactuators for'insuring the maintenance of one electro-magneticactuatoran actuated-1 position, while another electro-magnetic actuator is in anunactuatedposition.

Still another object of my inventionis to provide a novel constructionof a mechanical interlock for a pair` of electro-magnetic actuators'foroperation ofhigh frequency-contactera set forth Vmore fullyin the;specification hereinafter following by reference to the accompanyingdrawings in which:

Figure 1 is afrontplanview of the interlocking transfer switch of myinvention; Fig.w2 is a. reary plan View of. the interlockingy transferswitch of my invention; Fig. 3 is` a. side View ofY the interlockingtransfer switch lookingin the direction of arrow AY of Fig.1';"figqlvisanV end. View of the interlocking transfer switch looking inthe direction of. arrow B ofFig., 1v withcertain of the partsomitted to.avoid confusion; Fig. 5" is an enlarged transverseyerticalSGCtional'view taken substantially on liney 5-5 of Fig,3;Fig. 6"y is anenlarged horizontaly section takensubstantially on line 6--6 of "Fig,-`3 withtheelectro-mag.- netic actuators in the sameposltion asrthlatillustrated in Fig. 1'; Fig. 7 isr avview similar to the viewillustrated in Fig. 6." but Showingv the actu-` atorsY in a positionopposteto the positionillustrated in Fig. 6; Fig, 8 isa. transversesectional Viewk takenl substantially online 8--8 of. Figs. 1. and 3;Fig. 9` is a longitudinal sectional View takenfsubstantiallyf'on line9--9=of"Fig; I; Fig. 10 is avdetail view-illustrating one of themechanical' stops carried by the reciprocative members whicharecontrolled bythe electro-magnetic actuators, the view being takensubstantially on line lll-I0 of Fig; 1'; Fig. 1lV is a detail view takensubstantially online ll---Hr of Fig. v1 and illustrating one of lthefixed contacts employed `in the high frequency switch contact-employedin the-switch of my invention; Fig. 12- is a perspective view'ofbneofthe abutment angles used in association with the stationary-contactsof the switch construction of myinvention; Figf. 13-is any enlarged planview-illustrating the interlocking: mechanism employed Ain the switch ofmyl invention with parts illustrated in the same position asset forth inFig. l; Fig. 14 is a perspective View ofthe left endcontrol link in theinterlocking-mechanismof Fig. 13; Fig. 15 isa perspective view ofthe-right end-link of. the-interlocking mechanism illustratedin Fig. 13;and-Fig. 16is a schematic and' diagrammatic View illustrating the highfrequency interlocking, transferswitch of my. invention.

Referring to thedrawings in detail, reference cl'xari-rcter l.represents-ay panel structure of insulation material such asMicalex orBakelite. which supports thei elements ofi thefinterlockingtransferswtch ofmyiinvention. Adjacent one end of thepanelestructure l1It provide supporting members.; 2 I and 3,; for the movable` contactorsofthe switch ofg'my,y invention.. The supporting members); and 3:.havescrew.-threaded'portionsv 2a and 3ay which."projectythrough. the. panelstructure l. Intermediategthe screw@threaded end 2a and the oppositeprojectingv end. off supporting member V2 I provide; cylindrical*portions 2li-.and 2c which serve as bearing supports for. thek tubularcylindrical sleeve-fl k which ispfreefto, rock, abouty the cy.-lind-rical, portions Zhand 2c.. 'T o.f provide for the pivotal mounting;and restricted: movement of sleeve 'I Igformashoulder 2d on. supportingmember 2 which serveszao limit; for the movable Sleeve- Tfandcoronashieldflikemembers Va' and. sin.

which the corona shield-likememben 4'V serves as.; the opposite limit.for; thel angularly movable tubular sleeve-like member 'l and theAcorona shield. 6 serves as.'v ai nut; engaging screw threads 2a on theopposite sidevl of panel l, with` the lockwasher 5 interposed betweenthe.: corona shieldl The sleeyerlike member l;

55 thereto by screws 8a.

A multi-leaved contacter 9 is secured by screws I9 to the opposite sideof the block 2c. The multileaved contacter projects on opposite sides ofthe supporting member 2 in opposite directions and terminates in themovable contactors I4 and I5 which serve to establish alternateelectrical connections with the aligned ixed contactors IE and I1supported bythe panel structure Ij. Ihe multileaved contacter 9sec`uredthrough screws I0 to block 2e serves as a flexible mechanical supportingmeans for the multiple phased high frequency contactors I4 and I5.Electrical connection is established with the multi-leaved contactor 9through the iiexible connector I I secured at the end I2 to thesupportingmember 2 and at the opposite end by means of screws I3 to themulti-leaved contacter 9. Thus an electrical connection made at terminalI2 to the'cennector II is a circuit to the angularly rockablemulti-leaved contacter 9.

The ixed contactors I Iiandullare arranged for high,` frequencyelectrical Connection with minimum corona losses by reason oftheelectrical shieldswhich are associated with the xed contactors. 4Forexample., the xed contacter I3 comprises an angle member shown moreclearly in F1g. 1 2. having an attachment portion Isa which bearsdirectly against the corona shield ISb securedin position by-screws 16ewhich pass through the corona shields I Id and ISb and into the anglesupport-v Ijd of the yi'ixed contacter. A binding post I6@ is attachedtothe extension Id of the fixedcontacten .v

. The vfixed contacter AI1 isi s` ilar to the arrangement of thefixedcontacter I6, that is, the angle support Ila, attached te the contactl I1 is secured in .position -by .nieansof s crewsg I 1e which pass throughthey corona;lshields; -l1d :and 11b.. -The binding post I1c is carriedby the Iangle support I 1a.A The shaping of `the xed contacters is suchthat minimum-corona'discharge cani occur due to theloss ofenergywhichmight, ordinarily occur at sharpcorners of the contactors.

In spaced relation to the fixed-contactors I6 and I1, I provide anotherset of fixed lcointa'ctors I8 and I9whichare located at sucndistancesfrom the multi-leaved contacter 9-and fixed .con.V tactors I6 vand I1that no discharge can-occur therebetween. IThe nXed-fcontactorIBincludes an angle portion I8a which is supported withrespect to panelI by suitable screws le passing throughV corona shields I8b and Id.vBinding post I8c isY provided forV establishingconnection -to the fixedcontacter I8. The corona shields.I8b and I'Sd areeach spaced from thepanell by spacer members- Igfand Ih. andsecuredbyscrewsIfy;

Similarly, the high frequencyzxed vcontacterf I9 is formed by. anglemember I9a havingfsecuring screws I9e extending :through the coronashields I9d and I Sb and through the vpanel lstructure l formaintainingthe xed contacter inthe path of the co-acting multi-leaved.movable contacten The second movable contacter is like the firstangularly rockable contacter heretofore described in that an angularlyrockable sleeve 20A is mounted on the supporting .member` 3 which isprovidedwith annular shoulders 3band v3c over which the sleeve 20 isadapted .to angularly rock'. A block 28ek is secured to .thesleeve A2U'and serves as a support for the arm actuator 2l which projects onopposite sides of block 28e and is secured by" means of screwsZIa-extendinginto block 28e. A multi-leaved contacterl 23 issecuredtoljthe opposite side of block 20e`by securingscrewsl 4 formechanically mounting the angularly rockable multi-leaved contacter 23in position. A flexible connector 25 is secured by screws 26 to themulti-leaved contacter 23 and extends to the binding post 21 at theopposite end which is secured in the end of supporting member 3. Thus,as the sleeve 2|] angularly rocks about supporting member 3 theyiiexibleconnector v25 is free to iiexformaintaining electrical connection to themulti-leaved contacter 23 while maintaining the electrical circuittherethrough. 'Ihe multi-leaved contactor23 carries high frequencycontactors 28 and'29 on opposite ends thereof aligned with the Xedcontactors I8 and I9.

The multi-leaved contactors 9 and 23 are each rsimultaneously controlledabout the centers of supporting members 2 and 3 by an arrangement vofinsulated bar members 38 and 3i which are mounted for restrictedreciprocative movement. The bar members 30 and`3I may be formed fromMicalex, Bakelite orether suitable insulation material forminimum lossesat high, frequency operation. The b ar .members 38 and' 3l each cofactwith the arniactuators Sand .-2I for effecting longitudinal movementofthe bar-members under electromagneticoperation. `The paths of movementof insulatedbars 30 and 3| are controlled by atransversely lextendingguide bar 132 of insulation material. The guide bar 32 is supported atopposite ends Vupon'therear ofthe fixed contactors I8 and .I9 asillustrated more clearly in Fig. 11. The supporting boltV member 33extends from the rear of the xed contacter I8 and passes through `thebar 32 and is securedin position by the nut member vin the form of acorona shield 34a. The support for-the opposite end of-the bar 32 issimilar to the support already explained in that bolt member34extendsffrom the rear of contacter ISand passes through bar 32 and issecured by corona shield nut'` member 34a.

In ordertereduce the friction of movement of the-bars 3 8 and 3|-vthrough insulated bar 32 Iprovide recesses35a and 36a immediately behindthe slots 135an d36 :in bar 32 which guide the longitudinally extendingbars 38and 3I. These cutouts or recesses 35a and 36a substantiallyreduce the vsurface contact between bar 32 and the longitudinallyextending bars 3 and 3l while providing for the required guiding Aof thebars 30.2Iid3I-.

The bars 3 0V and 3l veach carry transversely extending pins. which Ihave represented lat 31 and 39 with respect tobar. 38 and at r38 and 40with respect te Ybar 3I'.`The`.pins 31'and 39V extending through bar 30are each secured in posi- -tion byv corona shieldelike members 31a -31band 39e-43919. The.tfransverse`pin members 38 and 48YfeXt'ei'idingthflfOugli bar `3I are each secured in position bylcor'onashield-like members 38a.- 33b..and 40%4019. f The'pri'lhmbers 31-39 and38..-4'0 serve asia lost motion vconnecting meansforestablishingfop'erating connection with the arm actuators 2Ifand 8.Thus when bar 30 is shifted tothe position illustrated in'lig.v l, thetransverse pininembers -31 and 39 engage beneath thejextensionslofarms'y 2I a'nd iinpartingrocking' movement to the block' members 20erand 2e ina ceiniter-clockwisev direction thereby moving h ighfrequehcy'contactors 28. andIII into surface Contact and connectionwithffi'xed contactors I8 f and I6 while 'simultaneously shiftingvcontactors 2:9 vand I 5, outof connection with fixed'contactors I9va'r1cl'I1'. v A Similarly, the transverse pinmembers 3.8 and 40carried'by longitudinally movable bar3ft .engage beneaiththe .ends'ofarm' actuators ascenso :I and swhen par al isssnifp-ted mmedirecuon ofarrow 4Il forfclosingfelectrical connection be tween movable contacter'r29:-andY fixed cont-actor I9 and between movable contactor I5 and fixedcontactor I1. The movement of barsv 30- and 3I in opposite directionsserves to positively control the rocking movement ofthe multi-leavedvcon-` tactors 23 and 9- for alternately est'ablishingand breakingelectricall co'rm'ect-ionbetweenthe-sets of movable andfixed`contactors.

The electro-magnetic operating mechanism which controlsv the rockingmovement of the'contactors as heretofore ldescribed, comprises a pair ofsolenoid' devices representedf at 42 and- I3-y '15 able frame members 44and'45 attachedjto theA mounted on the panel structure I throughsuitfield magnet structure IIS-and 4.1 'ofthe' solenoid devicesandsecuredithrough suitable bolts tothe` panel structure I'. Each magneticactuatorinj-A cludes a terminal board structure 48'and` 49upon; whichthe several terminals of the'electro-ma'g.

netic windings 42 and 43 Aare mounted asrepreL tening means representedat54a and 55a to the ends of the bars 3%) and 3l respectively. Thefastening means centers"thestrap structure 54 and 55 With respect to thecenter lines of' the longitudinally extending'bars 30 `and 3| therebyinsuring the balanced andr symmetrical operation ofthe switch. The strapmembers 54' and 55 serve to secure the armature members`52 and 53 in apositionr in whichltheyv are presented directly to the electro-magnetic:core structure of the electro-magnetic operating" mechanism when theassociated electro-magnetic winding' is energized.

The armature' members 52 and 53 e'achcarry panels cf insulation material5Sv and 5'I'associated therewith for supporting sets of auxiliarycontactors. structure 56`as carryingl the auxiliary contactors 58 and 59aligned with sets of 'xed contactors 55 and 6I supported byVthefauxiliary panelstructure 62 attached to the main panel' I. It willbe observed that the sets of contactors 58, are oppositely arranged withrespect to the sets of contactors 59 so that When contactors 58` areelectrically connected with contactors 5U, contactors 59 are open withrespect to contactors E I'. Similarly, the insulated. panel structure 51of the opposite electro-magnetic operating mechanism carries sets ofcontactors 63 and 64 aligned to co-act with sets of iixed contactors65and 65 in such manner that when` the electrical circuit betweencontactors 53 and (i5 is closed the electrical circuit betweencontactors 66 and contactors 64 is open. Other arrangements of auxiliarycontacts may be provided for the control or" any required number ofelectrical circuits such as the power circuits of an electrical systemasson ciated withl the high frequency circuits controlled by contactors253-18; I4-It;` 2li-I9; and I,5II. A

In order to insure against accidental-operation In Figs; 1 and 4 Irepresented panel" of the -highf frequency-ccntactors-A at' times-when:Jsuch `operation might be y dangerous or'Y injurious A to the associatedelectrical circuits, I provide-anovel construction of interlockvforcontrollingthe transfer switch. The-interlock isshown moreparticularly inFig-s. 6, 7, 13; 14; and 15 comprising a multiplicity ofsymmetrically arrangedpivotally mounted latchesv 61-L168- 69l andA 'I3journaled with respect-'toth'eepa'nell I- onfcenters representedv at'lI,12, 13, and'14'. YTheilatches are symmetricallyshapedl and itwill lbeobserved thatthe end'latchesAG'I and 1I)k are each-providedv withsubstantially semi-circularv -recesses t61aand ma therein to serveas'engage'ments and inter locks for roller members-52'aiand' 53arespectively Whereroller members 52aandf 53'asare1carried` by thearmature members 52 and 53 respectively.

The latches 68 and B9 areshaped-toprovidefcamlike faces 68d and 69dthereonea'ch cox-acting With roller members--5'2-liv and 536 carried.bythe Thelatches are pendantly mounted andof limite'dfswingingdisarmature members' 52 and? 53.

placement suicient to latch 1 ori unlat'chl the armature members52fvandi 53 inu either' of' two` ylimiting positions.

This interlocking operation is accomplished by providinganlarrangementof links interconnecting the pendantly mounted latches-as4 represented at 153 and-16 inI Figs. -15- and 14. The links V'I5and'I5 arelea'ch shaped to provide apair of projecting lugs 15a`f andz'l5b.ex-

tending-'infonedirection-and a-projecting lugi15c extending in theopposite direction and a pair. of projecting lugs `'IIiaand 1Gbextendinginone direction andan intermediate lug 16e-extending in theopposite direction. The 1lugs`-15a rand 15b are pivotally connectedWiththe latches'fl andl 69 respectively asrepresented at 61h and-'691).

The lugsV Gla-fandI'Ib'7 are pivotally: connected. with latches 68andlas representediatb: andv tend parallel facer to: face with respecttofeachi. This co-acting relation -serves to. providek an interlockingarrangementfor-the armature,

other. r

members 52 land-53 so. that thesemembers. are

maintained either in the` position. illustrated: in

Fig. 64 crv the position illustrated? in 7. atuthe opposite limitsof.`displacementl thereof;

The latches BT and. 'I0-.each provide-mountingY means for the platesofinsulation material repreE sentediat 'land 19; Platesf'landzg aresecured through suitableirivetsa 'I8a.and 'lfawor by. other means tothelatches Bf'IandJO'fa-ndff project angularly with respecttheretotoprovidef supportingfmeansfor the` operatingtpinl members and 8lrespectively. The; operatingy pin. members, 83 f and 8.1 havealimited-orbitk ofv movement for operating the controll contactors irepresented at.

82 `and 83. 'Ihecontrol contactorsZ and 83. are

supported by the terminal kpanels 485 and 49- as.

shown in Fig. 2V in the.positionswhichhave been superimposed forpurposesoi` explanation: upon Figs. 6 and 7 The-'controlcontactorsinclude the: binding posts.50 and 5I'.heretoforedescribedand aresilient leaf springY connection .between con.- trol contactors 82 and83-throughcoil springs,

82a and 83a to the postspwhich extendromjbind.-

ing posts 4822 and 49h respectively. Each ofzthe.

movable spring-likev contactors 182,. and. 83';v carry.r

contacts'A B2b and 83h onqthel ends; kthereon which,

are` adapted to,L register with andestablish connectionwith Athe postsl5I] and 5I respectively when spaciellvdsplaeed ibx engagement of pins80 andglftherewithff@hue it will. be seen that when` electro-magneticvwinding 42` is energized and armature member -52 ,magneticallyattracted by core structure 46, the armature member 52 moves to anengaged-positionin which it is maintained between latches 61, and 68whereupon pin 80 moves in a path whichengages spring contactor 82.shiftingecontactor B2b out of circuit connection withfbindingpost 5Uthus opening the electrical circuit' through the solenoid winding 42. oBy this movement, the armature 53 is released in the positionillustrated in Fig. 6 and in releasing conditions the ,electricalcircuit through the solenoid winding 43 by angularly shifting thecontactor83h into electrical connectiorrwith-lbindingpost5I. l Fig. 16schematically illustrates the'alternate electric vcircuit conditionsVwhich are thus provided. It will be seen that eachsof :the solenoidwindings 42 and 43 have separate control contacts in circuit therewithwhich are schematically shown at 84 and 85,. By-virtue of the fact thatcontactor 821: is displaced out of contacting relation with contactor 58as inthe arrangement illustrated in Fig. 6, the closing of switch 84will not energize solenoid winding 42 so that it is not possible toaccidentally operate the .transfer switch. The transfer switch is lockedinthe position in which contactcrs 28 and I8 and contactcrs I4 and ISare maintained in electrical connection until the operator positivelydesires to release the interlock and close contactsl 2S-I9 annd I5-I'Iwhereuponthe; Operator closes remote control switch 85.- .By virtue of1the conditionillustrated more clearly in vl'lig.- 6, an electricalcircuit may thus be completed through binding post 49h, contacter 83,contact 8,3b. binding post 5I through the source of potential andthrough switch 85 to binding post 49a and-through the solenoid winding43. Upon closing of the lremote control switch 85 armature .53 is drawnupwardly against the magneticgcore structure 41. lBy this movementvroller `member 53b moves against the face of cam-like latch 69 in aclock-Wise direction and shifting link 1,5 tothe leftiand pivoting ,linkl1 clockwise.y The -displacement, of link 61 has the effect ofreleasingarmature `member, 52 which drops byitsmass 'due 'to-.gravitythereby opening contacts 28-'I.3iand.I4-I6 by the drag, of pin members31 and 39 .against the multi-leaved contactors 23-9. At the Same timethe electrical circuit through solenoid winding `42 is conditioned bytheclosing of an electrical circuit through contact 42h and binding post5I! of the remote control circuit illustrated inEig. 16. Thus switch 84may thereafterbe closed at any desired time to activate solenoid winding42 for again closing contacts 28-I8 and I4I6. The relation of the partsof the interlock mechanism in this condition are illustrated in Fig. 7,but it will be observed rollerjmember 53 has been engaged withinthe-semi-circular recess a of the latch 10 for maintaining the ,armature53 in the actuated position; in,- which contacts 29-I9 and I5-I1 are.closed. Itpwill alsobe noted that` in this conditionthis power circuitthrough solenoid winding; has v'been .interrupted as pin 8| has caused`vafdisengageme'nt of .contact V83h from bindingY post 5I.: Thus it willbe observed that operation of the -high frequency. switch is ac-vcomplished by a momentary 'application offpower which; after beingapplied, is removed from the` 20.1` 1 5 are very simple in constructionand may thus .be manufactured on a quantity basis at low cost.

` cation offpowerv to solenoid winding 43 will have no eifect and it isonly possible to cause an opening of contacts 29-I9 and I5-I1 by closingremote control switch 84 which circuit has been conditioned asrepresented in Fig. 7 by the movement of contact 82h into register andconnection `with binding post 5B thereby preparing the circuit throughsolenoid winding 42 for activation from the remote control system. Underthese conditions contacts28-I8 and I4-I6 can be closed and contacts29-19 and I5-I1 can be opened.

The interlock is entirely symmetrical in its construction and has provenvery efficient in operation. .The pivotally mounted latches and theinterconnectingl links shown in Figs. 13, 14 and The auxiliary contactshave been represented in association with the insulated panel structures56 and 51 in certain specific arrangements, but it will be understoodthat various arrangements of auxiliary contacts may be provided and thatthe particular arrangements shown are for illustrative purposes only.Moreover, I have illustrated the high frequency contactcrs as limited toa pair of contact systems whereas any multiple number of high frequencycontactors may beprovided and operated according to the principles of myinvention. The auxiliary contacts may be entirely omitted if desired.Because-of the lexiblecircuit arrangementof the contact systems of myinvention it is entirely possible to arrange connections from a loadcircuit to the terminals 21 and I2 of the standards 3 and 2 Yand arrangeconnections to power circuits of diifering frequencies to contactcrs I6and I8 and to contactcrs I1 and I9 respectively. That is, a powercircuit of one frequency may terminate at contactcrs I6 and I8 and apower circuit of another frequency may terminate at contactcrs I1 and I9and either of these high frequency power circuits may be impressed upona load connected to the terminals I2 and 21. In lieu of the arrangementjust described, two separate loads may terminate at the terminals I6`I8and I1-I9 respectively and a highv frequencyv power system connected tobindingypostsv 21-I2 may be impressed upon either of the loadsselectively.

As heretofore observed, care is taken to round all discharge points ofthe high frequency switch system for minimizing possible losses due tocorona discharge at high frequencies for which the transfer switchsystem of my invention has. been designed. The magnetic actuating func-"tions of the switch are maintained at such a distance from the highfrequency contactoriunctions of the switchjthat discharge therebetweenor losses due to tendency of such discharge is eliminated.

While I have described my invention incertain of its preferredembodiments, I realize that changes and modifications may be made and Iintend no limitations upon my invention otherlimitingpositions'a'Teshaped'fterminus on each 4of said control members,anelectromagnetic ac.- tuator for controlling each of saidcontrolmembers, an electromagnetic Winding for operating each of saidelectromagnetic actuators, a control switch for each oi saidelectromagnetic windings.

'means pivotally mountedwith respect to said ysuplvlorting base andcoacting separate fswitch operatorsmovable bysaid control members and`ensageable by theaioresaidmeans vfor conditioning-saidcontrolswitchesby movement oi one of said c ontrolswitchesto iopenposition vwhen one v-of .said Yelectromagnetic actuators eis ener-'gized `andby .movement-,of Athe'aotlfier oisaid 'con-`trol-switches,.to ,closed position when the other ofsaid'relectromagnetic `actuators is "energized .and meansclisposedlbetwe'enfthe adjacentends of the T-shapedterminuson-each ofsaid reciprocative control members for alternately latching andAunlatching said controlmembers injposition 'for :maintaining `said`controly switches open or closed.

2. An interlocking transfer switch comprising a supporting base ofinsulating material, a pair of reciprocative control members havingdownwardly depending T-shaped termini thereon, movable in substantiallyspaced linear paths to either of two limiting positions, anelectromagnetic actuator for controlling each of said control members,pairs of angularly movable members, each pivotally mounted with respectto said base and symmetrically arranged on opposite sides of saidcontrol members, said angularly movable members each having cam shapedfaces thereon, one angularly movable member of each of said pairs ofangularly movable members being located in positions between saidreciprocative control members in alignment with the adjacent ends of theT-shaped termini thereon and one angularly movable member of each ofsaid pairs of angularly movable members being located in alignment withthe outside ends of the T-shaped termini said reciprocative controlmembers each carrying cam engaging members on the T-shaped terminithereof operative to establish interlocking relation with the cam shapedfaces of said pairs of angularly movable members for retaining one ofsaid reciprocative control members in one limiting position while theother of said reciprocatve control members is retained in an oppositelimiting position.

3. An interlocking transfer switch comprising a supporting base ofinsulating material, a pair of reciprocative control members, movable insubstantially spaced linear paths to either of two limiting positions,an electromagnetic actuator for controlling each of said controlmembers, pairs of pendently mounted angularly movable members, eachpivotally arranged on opposite sides of said control members, saidpendently mounted angularly movable members each having cam shaped facesthereon, said reciprocative control members each carrying cam engagingmembers on the T-shaped termini thereof, establishing interlockingrelation with the cam shaped faces of said pairs of angularly movablemembers for retaining one of said reciprocative control members in onelimiting position while the other of said reciprocative control membersis retained in an opposite limiting position, and a control switchindividual to one of each of said pairs of said angularly movablemembers for controlling the circuits through said electromagneticactuators.

4. An interlocking transfer switch comprising a supporting base fofinsulating material, a pair vof reciprocativecontrolmembers .havingdownwardly depending. T-shaped termini, movable in substantially..spaced lineair ,paths to either of two limiting positions, anelectromagnetic actuator for ,controllingeach.ofI said control members,aypairof roller 'members carriedby each of said reciprocative-,controlmembers 4on the T-shaped ,termini thereof, sets of angularly movablelmemable. members for eflectinglalterna-te engagement and disengagementofcsaid jangularly movable fnrembers=withthe roller members carried bysaid reciprocative control-members ein. alternately `opposite limitingpositions." f

5. Aninterlocking transfer switch comprising a supporting base ofinsulating material, a pair of reciprocative control members, movable insubstantially spaced linear paths to either of two limiting positions,an electromagnetic actuator for controlling each of said controlmembers, a pair of roller members carried by the T-shaped termini ofeach of said reciprocative control members, sets of angularly movablemembers pivoted on said base in coacting relation to the roller memberscarried by said reciprocative control members, one angularly movablemember of each of said sets constituting a roller engaging and holdingmeans and another angularly movable member of each set constituting arelease means for said roller engaging and holding means, and linksinterconnecting the roller engaging and holding means of one set ofangularly movable members with the roller engaging and release means ofanother set of said angularly movable members for effecting alternateengagement and disengagement of said reciprocative control members inalternately opposite limiting positions.

6. An interlocking transfer switch comprising a supporting base ofinsulating material, a pair of reciprocative control members, movable insubstantially spaced linear paths to either of two limiting positions,an electromagnetic actuator for controlling each of said controlmembers, a pair of roller members carried by each of the T-shapedtermini of said reciprocative control members, sets of angularly movablemembers pivoted on said base in coacting relation to the roller memberscarried by said reciprocative control members, one angularly movablemember of each of said sets constituting a roller engaging and holdingmeans and another angularly movable member of each set constituting arelease means for said roller engaging and holding means, linkspivotally connected between one of said roller engaging and holdingmeans and one of said roller release means for said roller engaging andholding means of each of said sets of angularly movable members, andspring means interconnecting each of said links for effecting alternateengagement and disengagement of said reciprocative control members inalternately opposite limiting positions.

7. An interlocking transfer switch comprising a supporting base ofinsulating material, a pair of reciprocative control members, movable insubstantially spaced linear paths to either of two limiting positions,an electromagnetic actuator for controlling each of said controlmembers, a pair or" roller members carried by the T-shaped termini ofeach of said reciprocative control members, sets of angularly movablemembers pivoted on said base in coacting relation to the roller memberscarried by said reciprocative control members, one angularly movablemember of each of said sets constituting a roller engaging and holdingmeans and another angularly movable member of each set constituting arelease means for said roller engaging and holding means, linkspivotally connected between one of said roller engaging and holdingmeans and one of said roller release means for said roller engaging andholding means of each of said sets of angularly movable members, andspring means interconnecting each of said links for effecting alternateengagement and disengagement of said reciprocative control members 'inalternately opposite limiting positions said links extendingsubstantially parallel to each other intermediate said angularly movablemembers andl said base.

JOSEPH F. FRESE.

l2 REFERENCES CITED UNITED STATES PATENTS Number Name Date 784,064Nordenberg Mar. 7, 1905 965,671 Whittingham July 26, 1910 1,156,502Seede Oct. 12, 1915 1,169,174 McLauthlin et al. Jan. 25, 1916 1,918,732Adams July 18, 1933 2,059,306. Bianco 1 Nov. 3, 1936 2,108,634 WilmsFeb. 15, 1938 2,144,665 Rasmussen Jan. 24, 1939 2,318,554 Raney May 4,1943 2,359,606 Ballou Oct. 3, 1944 2,459,255 Von Glahn Jan. 18, 1949FOREIGN PATENTS Number Country Date 24,003 Great Britain Sept. 28, 1911

